Aggregator

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1001 AM CST Fri Dec 29 2023 Valid 291630Z - 301200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected through Saturday morning. ...Northern/central CA coast through Saturday morning... No changes to previous outlook. In association with a midlevel shortwave trough moving eastward, a front and coincident rain band will spread inland over the central/northern CA coast late today into tonight. Gradual steepening of low-midlevel lapse rates as the mid levels cool will contribute to weak buoyancy rooted near the surface within and west of the frontal band. Isolated low-topped thunderstorms will be possible, primarily near the coast tonight through Saturday morning. ..Thompson/Squitieri.. 12/29/2023 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0637 AM CST Fri Dec 29 2023 Valid 291300Z - 301200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight across the Lower 48 states. ...Synopsis... Water-vapor imagery early this morning shows a potent mid- to upper-level trough near -130 deg W moving east towards the West Coast. This large-scale trough will reach the CA coast by early Saturday morning. Cold-air advection in the mid levels associated with the approaching trough and increased large-scale forcing for ascent, will favor the development of showers and a few thunderstorms moving ashore from Point Conception to southwest OR. Pockets of scant instability will likely limit both thunderstorm coverage/intensity. Elsewhere across the contiguous U.S., surface high pressure will influence conditions and be hostile for thunderstorm activity. ..Smith/Marsh.. 12/29/2023 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0637 AM CST Fri Dec 29 2023 Valid 291300Z - 301200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight across the Lower 48 states. ...Synopsis... Water-vapor imagery early this morning shows a potent mid- to upper-level trough near -130 deg W moving east towards the West Coast. This large-scale trough will reach the CA coast by early Saturday morning. Cold-air advection in the mid levels associated with the approaching trough and increased large-scale forcing for ascent, will favor the development of showers and a few thunderstorms moving ashore from Point Conception to southwest OR. Pockets of scant instability will likely limit both thunderstorm coverage/intensity. Elsewhere across the contiguous U.S., surface high pressure will influence conditions and be hostile for thunderstorm activity. ..Smith/Marsh.. 12/29/2023 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0637 AM CST Fri Dec 29 2023 Valid 291300Z - 301200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight across the Lower 48 states. ...Synopsis... Water-vapor imagery early this morning shows a potent mid- to upper-level trough near -130 deg W moving east towards the West Coast. This large-scale trough will reach the CA coast by early Saturday morning. Cold-air advection in the mid levels associated with the approaching trough and increased large-scale forcing for ascent, will favor the development of showers and a few thunderstorms moving ashore from Point Conception to southwest OR. Pockets of scant instability will likely limit both thunderstorm coverage/intensity. Elsewhere across the contiguous U.S., surface high pressure will influence conditions and be hostile for thunderstorm activity. ..Smith/Marsh.. 12/29/2023 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0637 AM CST Fri Dec 29 2023 Valid 291300Z - 301200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight across the Lower 48 states. ...Synopsis... Water-vapor imagery early this morning shows a potent mid- to upper-level trough near -130 deg W moving east towards the West Coast. This large-scale trough will reach the CA coast by early Saturday morning. Cold-air advection in the mid levels associated with the approaching trough and increased large-scale forcing for ascent, will favor the development of showers and a few thunderstorms moving ashore from Point Conception to southwest OR. Pockets of scant instability will likely limit both thunderstorm coverage/intensity. Elsewhere across the contiguous U.S., surface high pressure will influence conditions and be hostile for thunderstorm activity. ..Smith/Marsh.. 12/29/2023 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0637 AM CST Fri Dec 29 2023 Valid 291300Z - 301200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight across the Lower 48 states. ...Synopsis... Water-vapor imagery early this morning shows a potent mid- to upper-level trough near -130 deg W moving east towards the West Coast. This large-scale trough will reach the CA coast by early Saturday morning. Cold-air advection in the mid levels associated with the approaching trough and increased large-scale forcing for ascent, will favor the development of showers and a few thunderstorms moving ashore from Point Conception to southwest OR. Pockets of scant instability will likely limit both thunderstorm coverage/intensity. Elsewhere across the contiguous U.S., surface high pressure will influence conditions and be hostile for thunderstorm activity. ..Smith/Marsh.. 12/29/2023 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0637 AM CST Fri Dec 29 2023 Valid 291300Z - 301200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight across the Lower 48 states. ...Synopsis... Water-vapor imagery early this morning shows a potent mid- to upper-level trough near -130 deg W moving east towards the West Coast. This large-scale trough will reach the CA coast by early Saturday morning. Cold-air advection in the mid levels associated with the approaching trough and increased large-scale forcing for ascent, will favor the development of showers and a few thunderstorms moving ashore from Point Conception to southwest OR. Pockets of scant instability will likely limit both thunderstorm coverage/intensity. Elsewhere across the contiguous U.S., surface high pressure will influence conditions and be hostile for thunderstorm activity. ..Smith/Marsh.. 12/29/2023 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0359 AM CST Fri Dec 29 2023 Valid 011200Z - 061200Z ...DISCUSSION... A progressive upper pattern is forecast through the extended forecast period, with multiple shortwave troughs advancing eastward across the CONUS. A southern-stream shortwave trough should move from northern Mexico and the Southwest across the southern Plains from Day 4/Monday into Day 5/Tuesday. With a cold frontal intrusion expected into the northern Gulf of Mexico, low-level moisture return ahead of this upper trough should remain rather limited. While some potential for mainly elevated thunderstorms is apparent across parts of TX Tuesday afternoon and night, severe thunderstorms appear unlikely owing to the weak instability forecast. Medium-range guidance is in reasonably good agreement that this shortwave trough will merge with another upper trough and amplify as it moves quickly eastward across the Gulf of Mexico and Southeast from Day 6/Wednesday into Day 7/Thursday. With an associated surface low progged to scrape along or just south of the Gulf Coast, severe potential will likewise tend to remain offshore where greater low-level moisture should exist. Another upper trough/low may advance quickly eastward from the Southwest across the southern Plains and lower MS Valley late next week. But, the lack of appreciable low-level moisture over land suggests that overall severe potential should remain low through Day 8/Friday. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0359 AM CST Fri Dec 29 2023 Valid 011200Z - 061200Z ...DISCUSSION... A progressive upper pattern is forecast through the extended forecast period, with multiple shortwave troughs advancing eastward across the CONUS. A southern-stream shortwave trough should move from northern Mexico and the Southwest across the southern Plains from Day 4/Monday into Day 5/Tuesday. With a cold frontal intrusion expected into the northern Gulf of Mexico, low-level moisture return ahead of this upper trough should remain rather limited. While some potential for mainly elevated thunderstorms is apparent across parts of TX Tuesday afternoon and night, severe thunderstorms appear unlikely owing to the weak instability forecast. Medium-range guidance is in reasonably good agreement that this shortwave trough will merge with another upper trough and amplify as it moves quickly eastward across the Gulf of Mexico and Southeast from Day 6/Wednesday into Day 7/Thursday. With an associated surface low progged to scrape along or just south of the Gulf Coast, severe potential will likewise tend to remain offshore where greater low-level moisture should exist. Another upper trough/low may advance quickly eastward from the Southwest across the southern Plains and lower MS Valley late next week. But, the lack of appreciable low-level moisture over land suggests that overall severe potential should remain low through Day 8/Friday. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0359 AM CST Fri Dec 29 2023 Valid 011200Z - 061200Z ...DISCUSSION... A progressive upper pattern is forecast through the extended forecast period, with multiple shortwave troughs advancing eastward across the CONUS. A southern-stream shortwave trough should move from northern Mexico and the Southwest across the southern Plains from Day 4/Monday into Day 5/Tuesday. With a cold frontal intrusion expected into the northern Gulf of Mexico, low-level moisture return ahead of this upper trough should remain rather limited. While some potential for mainly elevated thunderstorms is apparent across parts of TX Tuesday afternoon and night, severe thunderstorms appear unlikely owing to the weak instability forecast. Medium-range guidance is in reasonably good agreement that this shortwave trough will merge with another upper trough and amplify as it moves quickly eastward across the Gulf of Mexico and Southeast from Day 6/Wednesday into Day 7/Thursday. With an associated surface low progged to scrape along or just south of the Gulf Coast, severe potential will likewise tend to remain offshore where greater low-level moisture should exist. Another upper trough/low may advance quickly eastward from the Southwest across the southern Plains and lower MS Valley late next week. But, the lack of appreciable low-level moisture over land suggests that overall severe potential should remain low through Day 8/Friday. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0359 AM CST Fri Dec 29 2023 Valid 011200Z - 061200Z ...DISCUSSION... A progressive upper pattern is forecast through the extended forecast period, with multiple shortwave troughs advancing eastward across the CONUS. A southern-stream shortwave trough should move from northern Mexico and the Southwest across the southern Plains from Day 4/Monday into Day 5/Tuesday. With a cold frontal intrusion expected into the northern Gulf of Mexico, low-level moisture return ahead of this upper trough should remain rather limited. While some potential for mainly elevated thunderstorms is apparent across parts of TX Tuesday afternoon and night, severe thunderstorms appear unlikely owing to the weak instability forecast. Medium-range guidance is in reasonably good agreement that this shortwave trough will merge with another upper trough and amplify as it moves quickly eastward across the Gulf of Mexico and Southeast from Day 6/Wednesday into Day 7/Thursday. With an associated surface low progged to scrape along or just south of the Gulf Coast, severe potential will likewise tend to remain offshore where greater low-level moisture should exist. Another upper trough/low may advance quickly eastward from the Southwest across the southern Plains and lower MS Valley late next week. But, the lack of appreciable low-level moisture over land suggests that overall severe potential should remain low through Day 8/Friday. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0359 AM CST Fri Dec 29 2023 Valid 011200Z - 061200Z ...DISCUSSION... A progressive upper pattern is forecast through the extended forecast period, with multiple shortwave troughs advancing eastward across the CONUS. A southern-stream shortwave trough should move from northern Mexico and the Southwest across the southern Plains from Day 4/Monday into Day 5/Tuesday. With a cold frontal intrusion expected into the northern Gulf of Mexico, low-level moisture return ahead of this upper trough should remain rather limited. While some potential for mainly elevated thunderstorms is apparent across parts of TX Tuesday afternoon and night, severe thunderstorms appear unlikely owing to the weak instability forecast. Medium-range guidance is in reasonably good agreement that this shortwave trough will merge with another upper trough and amplify as it moves quickly eastward across the Gulf of Mexico and Southeast from Day 6/Wednesday into Day 7/Thursday. With an associated surface low progged to scrape along or just south of the Gulf Coast, severe potential will likewise tend to remain offshore where greater low-level moisture should exist. Another upper trough/low may advance quickly eastward from the Southwest across the southern Plains and lower MS Valley late next week. But, the lack of appreciable low-level moisture over land suggests that overall severe potential should remain low through Day 8/Friday. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0359 AM CST Fri Dec 29 2023 Valid 011200Z - 061200Z ...DISCUSSION... A progressive upper pattern is forecast through the extended forecast period, with multiple shortwave troughs advancing eastward across the CONUS. A southern-stream shortwave trough should move from northern Mexico and the Southwest across the southern Plains from Day 4/Monday into Day 5/Tuesday. With a cold frontal intrusion expected into the northern Gulf of Mexico, low-level moisture return ahead of this upper trough should remain rather limited. While some potential for mainly elevated thunderstorms is apparent across parts of TX Tuesday afternoon and night, severe thunderstorms appear unlikely owing to the weak instability forecast. Medium-range guidance is in reasonably good agreement that this shortwave trough will merge with another upper trough and amplify as it moves quickly eastward across the Gulf of Mexico and Southeast from Day 6/Wednesday into Day 7/Thursday. With an associated surface low progged to scrape along or just south of the Gulf Coast, severe potential will likewise tend to remain offshore where greater low-level moisture should exist. Another upper trough/low may advance quickly eastward from the Southwest across the southern Plains and lower MS Valley late next week. But, the lack of appreciable low-level moisture over land suggests that overall severe potential should remain low through Day 8/Friday. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0359 AM CST Fri Dec 29 2023 Valid 011200Z - 061200Z ...DISCUSSION... A progressive upper pattern is forecast through the extended forecast period, with multiple shortwave troughs advancing eastward across the CONUS. A southern-stream shortwave trough should move from northern Mexico and the Southwest across the southern Plains from Day 4/Monday into Day 5/Tuesday. With a cold frontal intrusion expected into the northern Gulf of Mexico, low-level moisture return ahead of this upper trough should remain rather limited. While some potential for mainly elevated thunderstorms is apparent across parts of TX Tuesday afternoon and night, severe thunderstorms appear unlikely owing to the weak instability forecast. Medium-range guidance is in reasonably good agreement that this shortwave trough will merge with another upper trough and amplify as it moves quickly eastward across the Gulf of Mexico and Southeast from Day 6/Wednesday into Day 7/Thursday. With an associated surface low progged to scrape along or just south of the Gulf Coast, severe potential will likewise tend to remain offshore where greater low-level moisture should exist. Another upper trough/low may advance quickly eastward from the Southwest across the southern Plains and lower MS Valley late next week. But, the lack of appreciable low-level moisture over land suggests that overall severe potential should remain low through Day 8/Friday. Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0218 AM CST Fri Dec 29 2023 Valid 311200Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Sunday. ...Synopsis and Discussion... An upper trough/low should progress eastward from the Upper Midwest and Great Lakes across the OH/TN Valleys on Sunday. A separate shortwave trough initially over the Southwest is forecast to move over the southern Plains through the day, and eventually merge with the eastern CONUS upper trough Sunday night into early Monday morning. With dry and/or stable conditions expected to persist over a large majority of the CONUS, thunderstorm potential should remain minimal, with one possible exception. Some low-level moisture should return northward across the northwest Gulf of Mexico and coastal TX late Sunday night ahead of the southern-stream shortwave trough. Enough weak MUCAPE may develop to support elevated thunderstorms from parts of the Upper TX Coast into LA through early Monday morning. ..Gleason.. 12/29/2023 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0218 AM CST Fri Dec 29 2023 Valid 311200Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Sunday. ...Synopsis and Discussion... An upper trough/low should progress eastward from the Upper Midwest and Great Lakes across the OH/TN Valleys on Sunday. A separate shortwave trough initially over the Southwest is forecast to move over the southern Plains through the day, and eventually merge with the eastern CONUS upper trough Sunday night into early Monday morning. With dry and/or stable conditions expected to persist over a large majority of the CONUS, thunderstorm potential should remain minimal, with one possible exception. Some low-level moisture should return northward across the northwest Gulf of Mexico and coastal TX late Sunday night ahead of the southern-stream shortwave trough. Enough weak MUCAPE may develop to support elevated thunderstorms from parts of the Upper TX Coast into LA through early Monday morning. ..Gleason.. 12/29/2023 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0218 AM CST Fri Dec 29 2023 Valid 311200Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Sunday. ...Synopsis and Discussion... An upper trough/low should progress eastward from the Upper Midwest and Great Lakes across the OH/TN Valleys on Sunday. A separate shortwave trough initially over the Southwest is forecast to move over the southern Plains through the day, and eventually merge with the eastern CONUS upper trough Sunday night into early Monday morning. With dry and/or stable conditions expected to persist over a large majority of the CONUS, thunderstorm potential should remain minimal, with one possible exception. Some low-level moisture should return northward across the northwest Gulf of Mexico and coastal TX late Sunday night ahead of the southern-stream shortwave trough. Enough weak MUCAPE may develop to support elevated thunderstorms from parts of the Upper TX Coast into LA through early Monday morning. ..Gleason.. 12/29/2023 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0218 AM CST Fri Dec 29 2023 Valid 311200Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Sunday. ...Synopsis and Discussion... An upper trough/low should progress eastward from the Upper Midwest and Great Lakes across the OH/TN Valleys on Sunday. A separate shortwave trough initially over the Southwest is forecast to move over the southern Plains through the day, and eventually merge with the eastern CONUS upper trough Sunday night into early Monday morning. With dry and/or stable conditions expected to persist over a large majority of the CONUS, thunderstorm potential should remain minimal, with one possible exception. Some low-level moisture should return northward across the northwest Gulf of Mexico and coastal TX late Sunday night ahead of the southern-stream shortwave trough. Enough weak MUCAPE may develop to support elevated thunderstorms from parts of the Upper TX Coast into LA through early Monday morning. ..Gleason.. 12/29/2023 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0218 AM CST Fri Dec 29 2023 Valid 311200Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Sunday. ...Synopsis and Discussion... An upper trough/low should progress eastward from the Upper Midwest and Great Lakes across the OH/TN Valleys on Sunday. A separate shortwave trough initially over the Southwest is forecast to move over the southern Plains through the day, and eventually merge with the eastern CONUS upper trough Sunday night into early Monday morning. With dry and/or stable conditions expected to persist over a large majority of the CONUS, thunderstorm potential should remain minimal, with one possible exception. Some low-level moisture should return northward across the northwest Gulf of Mexico and coastal TX late Sunday night ahead of the southern-stream shortwave trough. Enough weak MUCAPE may develop to support elevated thunderstorms from parts of the Upper TX Coast into LA through early Monday morning. ..Gleason.. 12/29/2023 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0218 AM CST Fri Dec 29 2023 Valid 311200Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Sunday. ...Synopsis and Discussion... An upper trough/low should progress eastward from the Upper Midwest and Great Lakes across the OH/TN Valleys on Sunday. A separate shortwave trough initially over the Southwest is forecast to move over the southern Plains through the day, and eventually merge with the eastern CONUS upper trough Sunday night into early Monday morning. With dry and/or stable conditions expected to persist over a large majority of the CONUS, thunderstorm potential should remain minimal, with one possible exception. Some low-level moisture should return northward across the northwest Gulf of Mexico and coastal TX late Sunday night ahead of the southern-stream shortwave trough. Enough weak MUCAPE may develop to support elevated thunderstorms from parts of the Upper TX Coast into LA through early Monday morning. ..Gleason.. 12/29/2023 Read more